Power windows roll up, but not down.

[RCM3]

Ive searched and searched for any threads offering insight to this issue but I havent found a solution yet. Yesterday my car was broken into (nothing serious taken, only the ashtrays as they were full of change, a knife, and some cologne) and since that moment my windows have not worked fully. Heres where I am at:

Sunroof works fine, opens, closes, tilts. I tested for power at the window switches, I have it. Also, I register power on the appropriate wire when I press the button to either roll the window up or down, however, only when I press the button to roll the windows up do the motors actually respond. What I find weird is that BOTH windows behave in the same way and started malfunctioning at the same time. Both windows roll up, but do no react when I try an roll them down (despite registering power at the switch when I press down). To double check I didn't have a faulty breaker I bypassed it and that changed nothing. Not that it should matter but I have e36 switches in the car now, have had them for a while and they've always worked great. My fuse isn't blown also.

Just wondering where I need to look next. I grabbed a wiring diagram from a thread and I just cant figure out how both motors would fail when it comes to rolling the window down. Haven't removed door panels yet to inspect anything.

Thanks for any help guys.

[dogsbark26]

It sounds like a down ground problem to me. IIRC the up uses one ground, down another.

[mcskibadee1]

I was having a similar problem where the window would only go up and not down and eventually stooped working altogether. This was passenger side only and I was registering power getting there. I went as far as to replace the motor and finally I just jiggled the wires that come from the door and lead into the cabin and they worked. Every once in a while it well happen again and I just mess with the wires and it works again.

Only weird thing is its happening to both your Windows.

[RCM3]

Ya it's still not solved. I took the panel off the door and unplugged the connector in the door jamb. Proving for power I get roughly 12v at the door connector, and then the same 12v at the motor plug (of course only getting it when I push the appropriate switch). I tried to run a jump line with 12v right into the motor plug to bypass the swotch to motor wiring and still couldn't get it to budge. Replacing both motors tomorrow with used but known working motors, hopefully that solves it. Still, the odds of both motors failing at the exact same time makes me think the motor swap won't work.

Regarding the comments about the ground. Based on the diagram I have and looking at the motor, I see no grounds at the motors. I know the switches have 2 grounds coming off, but the motors as far as I can see have only 2 power lines, one for up one for down. And my diagram only shows these two lines. I just am running out of places to look to solve the issue. I'll see how the repairs tomorrow go and post back.

[2l2ltq]

Did not read to far into this, but mine did the same thing and it was the switch. Both switches for front windows are the same. So swap them and see if that fixes it. If not then check the motor.

[DaveSmed]

Regarding the comments about the ground. Based on the diagram I have and looking at the motor, I see no grounds at the motors. I know the switches have 2 grounds coming off, but the motors as far as I can see have only 2 power lines, one for up one for down. And my diagram only shows these two lines. I just am running out of places to look to solve the issue. I'll see how the repairs tomorrow go and post back.

Those power lines rest on ground when not switched to up or down respectively.

So when the "up" wire has power, the "down" wire is the ground and vice versa.

This basically verifies circuit integrity for everything after the switch if the windows work at all.

[dogsbark26]

The grounds are supplied by the switches (there is no ground at motor) and are separate for up and down. I suspect the ground connection for the down side. The motor works (window goes up) leaving only the down ground (or switch but because neither side works, switch failure is unlikely) as a possible culprit.
Problem is not likely to be with motor (they work)!

[RCM3]

So I finally got everything working properly. As mentioned above, and thanks a lot it's what got the issue figured out, one switch had a problem with the ground part of the circuit when trying to roll or down. The other side had a bad switch. I didnt have any e36 spare switches so I could t swap another in (and for some reason when I swapped the two switches I did have in te car the window still didnt operate. So fixing the bad ground and a new switch solved the issues. Thanks again guys!

[dogsbark26]

Glad to hear. Enjoy.